JP2570992Y2 - Engine structure - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine structure.

[0002]

2. Description of the Related Art The structure of a front end portion of an OHC type diesel engine in a conventional vehicle such as a truck will be described with reference to a schematic front view of FIG. 3 and a schematic sectional view of FIG. In the drawing, reference numeral 10 generally indicates an OHC type diesel engine, which is composed of a crankcase 12 and a crankcase 1.
The cylinder head 14 includes a cylinder head 14 mounted on an upper end of the cylinder head 2 and a rocker cover 16 mounted on an upper end of the cylinder head 14. A crankshaft 18 is attached to the crankcase 12.
And a crank gear 20 is fixed to the crankshaft 18. The crank gear 20 meshes with an idler gear 24 rotatably supported by a gear shaft 22 fixed to the crank case 12.
An injection pump drive gear (not shown) that drives the cam shaft of the row type fuel injection pump is meshed. Further, a driving sprocket wheel 26 is coaxially fixed to the idler gear 24 and rotates integrally. A cam shaft 28 for opening and closing the intake valve and the exhaust valve is supported by the cylinder head 14.
, A driven sprocket wheel 30 is fixedly mounted. A timing chain 32 is wound between the driving sprocket wheel 26 and the driven sprocket wheel 30. A timing gear case 34 is mounted on the front end of the crankcase 12, and the above-described crank gear 20, idler gear 24, driving sprocket 26, and timing chain 32 are housed in the timing gear case 34.
A water pump casing 36 is fixed in front of the timing gear case 34, and the pump casing 3
Pump shaft 40 for driving impeller 38 housed in 6
, A driven pulley 42 is fixed. Driven pulley 4
2 and a driving pulley 44 fixed to the crankshaft 18.
And a V-belt 46 wound therearound.

As is best shown in the front view of FIG.
In the conventional engine, since the running path of the timing chain 32 and the casing 36 of the water pump interfere with each other in a projection plane orthogonal to the crankshaft 18, the water pump casing 36 is attached to the timing gear case 34.
Can not be housed inside. Therefore, as shown in FIG. 4, the water pump casing 36 is protruded in front of the timing gear case 34, and the entire length of the engine 10 is reduced by the dimension A in the front-rear direction of the water pump casing 36.
However, there are drawbacks that the weight and manufacturing cost increase, and that the mountability on a vehicle deteriorates.

[0004]

SUMMARY OF THE INVENTION The present invention reduces the overall length of the engine by reducing the overall length of the engine by devising the arrangement of the timing chain device including the above-mentioned timing chain and the driving and driven sprocket vehicles and the water pump. An object of the present invention is to reduce costs and improve mountability on a vehicle.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and is fixed to a driving sprocket wheel driven in conjunction with a crankshaft and a camshaft for opening and closing an intake valve and an exhaust valve. a timing chain system comprising a timing chain which is MekuSo to have been driven sprocket wheel and the driver sprocket wheel and the driven sprocket wheel,
An axial direction of the crankshaft of the crankcase is so set as to at least partially cover the outside of the timing chain device.
The timing gear case mounted on the side and the engine cooling
And a water pump for circulating cooling water
In the engine structure, the water pump is
The center axis of the crankshaft of the timing gear case
Of the timing chain on a projection plane orthogonal to
A recess formed in the outer wall portion at a position separated from the path,
Covering the recess on the outer wall of the timing gear case
Water pump cover and a water pump cover
Data pump housing and an inlet disposed in the recess.
The present invention proposes an engine structure characterized by comprising a propeller .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. (Note that members and portions that are substantially the same as or correspond to those of the conventional engine described above with reference to FIGS. 3 and 4 are denoted by the same reference numerals, and redundant description is omitted.) The casing 36 of the water pump is mounted on the outer wall of the timing gear case 34 separated from the travel path of the timing chain 32 in the front projection plane shown in FIG.
It is recessed toward two sides. In the casing 36,
An impeller 38 mounted on one end of a pump shaft 40 is accommodated. The pump shaft 40 is rotatably supported by a pump cover 48 mounted on a front opening of the casing 36. The traveling path on the side of the timing chain 32 adjacent to the water pump casing 36 is the crankcase 1
A tension lever 54 is provided along the other traveling path of the chain, which is limited by a fixed chain guide 52 fixed to a front plate 50 fixed to the front end of the second chain. The tension lever 54 is pivotally supported by the crankcase 12 via a pivot 56, and is pressed toward the chain 32 by a pressing member 58 which is constantly biased by a spring or the like. According to the above configuration, since the water pump casing 36 is formed integrally with the timing gear case 34 and is recessed on the crankcase 12 side, compared with the conventional engine shown in FIGS. The overall length of the engine is shortened by an amount substantially corresponding to the dimension A in the front-rear direction of the pump chamber, so that the engine weight and the manufacturing cost are correspondingly reduced, and the mountability to the vehicle is improved.

[0007]

[Effects of the Invention] As described above, the engine structure according to the present invention is composed of a driven sprocket vehicle driven in conjunction with a crankshaft, a driven sprocket vehicle fixed to a cam shaft for opening and closing an intake valve and an exhaust valve. a timing chain system comprising a MekuSo timing chain driver sprocket wheel and the driven sprocket wheel, at least partially cover as crankcase outside of the timing chain system
The timing gear case mounted on one side of the crankshaft in the axial direction and the cooling water for cooling the engine are circulated.
Engine structure with a water pump for
And the water pump is connected to the timing gear case.
The projection plane perpendicular to the central axis of the crankshaft.
Of the timing chain
A recess formed in the outer wall portion and the timing gear case;
Is attached to the outer wall of the
Water pump housing consisting of a water pump cover
And an impeller arranged in the concave portion, to shorten the overall length of the engine to reduce its weight and manufacturing cost, and to improve the mountability on a vehicle. This is practically useful.

[Brief description of the drawings]

FIG. 1 is a front view of one embodiment of the present invention, partly in section.

FIG. 2 is a longitudinal sectional view of a main part of the engine shown in FIG.

FIG. 3 is a schematic front view in which a part of a conventional engine is cut away.

FIG. 4 is a schematic longitudinal sectional view of the engine shown in FIG.

[Explanation of symbols]

 Reference Signs List 10 engine 12 crankcase 14 cylinder head 18 crankshaft 26 driven sprocket wheel 28 camshaft 30 driven sprocket wheel 32 timing chain 34 timing gear case 36 water pump casing 38 impeller

Claims (1)

(57) [Scope of request for utility model registration] 1. A driven sprocket wheel driven in conjunction with a crankshaft, a driven sprocket wheel fixed to a cam shaft for opening and closing an intake valve and an exhaust valve, and a timing chain wound on the driven sprocket wheel and the driven sprocket wheel. timing chain system and, axially one crankshaft at least partially cover as crankcase outside of the timing chain apparatus comprising a
The timing gear case mounted on the side and the engine cooling
And a water pump for circulating cooling water
In the above-mentioned engine structure, the water pump is provided so that the timing gear case has a central axis of the crankshaft.
In the projection plane orthogonal to the line, the timing chain
A recess formed in the outer wall portion at a position separated from the traveling path
And the above-mentioned recess in the outer wall portion of the above-mentioned timing gear case.
Consisting of a water pump cover that is combined to cover
An engine structure comprising a water pump housing and an impeller arranged in the recess .